Serbian news site b92 reports on the case of a man who passed a police polygraph test regarding the disappearance of a woman he has since confessed to having murdered. After passing the polygraph, Rajkovic allededly went on to rape and murder a three-year old girl.

Excerpt:

Murderer “passed lie detector test before killing again”

A man detained on July 10 on suspicion that he raped and murdered a 3-year-old child the day before, on June 24 passed a lie detector test “with no problem.”

Source: Vecernje novosti Tuesday, July 12, 2016 | 11:20

Belgrade daily Vecernje Novosti is reporting this on Tuesday.

The suspect, Vladica Rajkovic, took the polygraph test as part of a police investigation into the June 18 disappearance of Dragana Stefanovic. He has in the meantime confessed to murdering the woman, and told the police the details of his crime.

This case is a prime example of why it is FOOLISH and DANGEROUS to rely on the polygraph as a “lie detector”. Those con men who boldly make the fraudulent claim that they can detect deception by means of this crude and unreliable instrument are doing a grave disservice to those who believe the lies they are telling. It is dangerous to believe the polygraph operators who claim that they have the ability to detect deception by charting physiological reactions to questions. There is NO reaction that ALWAYS indicates deception – therefore there is no such thing as a “lie detector”! Many truthful people are falsely branded as liars and many liars are called truthful – with grave consequences. Shame on the polygraph operators who perpetuate the dangerous myth of lie detection – their only motivation is greed. And shame on those in positions of power who are deliberately ignorant of the fraud and abuse that is rampant in the evil polygraph industry.

“We must not deceive ourselves into thinking that there will ever be an error-free way of
detecting deception” – the last line in 2004 The British Psychological Society report – A review of the current scientific status and fields of application of Polygraphic Deception Detection. ( an excellent read)
A lot of time and effort in poor investigations is spent looking for lies, when good investigators should spent time and effort looking for checkable facts.